1. Field of the Invention
The present invention relates to a lock, and more particularly to a lock having a core capable of being activated/deactivated by a private key and a general key and having an indicator to indicate the application of the private key or the general key respectively.
2. Description of the Prior Art
A lock is provided with a latch controllably and operably by the mechanism of the lock core. That is, when the lock core of the lock is in a locked position, the latch is secured to the casing of the lock and when the lock core is in the open position, the latch is freely movable relative to the casing. However, this conventional lock has no ability to indicate whether the core has been tampered with by an authorized or unauthorized personnel (normally the unauthorized personnel). In order to show who has accessed to the lock, U.S. Pat. No. 7,007,521 and U.S. Pat. No. 6,877,345 both provide mechanism to indicate different status in response to the activation method applied to the core of the lock structure so that the subsequent user of the lock may have the information of who had used the lock before him/her.
However, there is a disadvantage in the lock structure mentioned in the above patents. That is, the user has to memorize the combination in order to activate the lock core mechanism. Furthermore, the lock structure is incapable of indicating whether any unauthorized personnel has ever attempting to activate the lock core.
To overcome the shortcomings, the present invention tends to provide an improved lock structure to mitigate the aforementioned problems.